Electromagnet construction



Filed Sept. 25, 1925 L J WAHL ELECTROMAGNET CONSTRUCTION Jan. 17, 1928.

Patented Jan. 17, 1928.

,UNITED STATES PATENT OFFICE.

LEO J. WAHL, OF STERLING, ILLINOIS.

ELECTBOMAGNET CON STRUGTION.

pers in which the coil of the electro-magnet extends transversely of thecasing of the device. In such a device, it is particularly importantthat the same is so constructed that it will have a minimum width at theportion thereof where it is gripped by the hand of the operator. It isaccordingly very important to make the coil and core of theelectro-magnet as short as is possible to still obtain the desiredamount of power therefrom.

It is particularly a purpose of my inven 1 tion to provide a core for anelectro-magnet of this of this character that is so constructed as toprovide a better path for the magnetic flux than has previously been thecase.

. It is articularly important in a device character to reduce the widthof the core portions that lie between theend of the coil and the casing.In order to do this, the thickness thereof is increased to thus obtainsubstantially the same cross sectional area for the portion of the corelying between the casing and the end of the coil as would be the case ifthe same were made of a greater width at said portion. This has beenpreviously accomplished by inserting lamiiations in the core that do notextend through the coil, but which extend transversely thereof betweenthe casing and the end of the coil. Preferably, these laminations haveend portions that are wider than the transversely extending portionsthereof so that icrews or other securing devices can be passed throughthe same for holding the same in position in the casing. The laminationsthat extend through the center of the coil are rovided with similartransversely extendmg portions havin similar ends. In thearrangement'with the inserted laminations or added laminations, however,there are numerous air gaps in the path of the flux due to the fact thatthe flow is partially, in the transversely extending portion of thecore, from certain laminations that continue into the center of the coilto the laminations that do not extend into said center.

It is a purpose of my invention to increase the efficiency of theelectro-magnet further by eliminating said air gaps. This isaccomplished by making the transversely extending portions of the coreor the portions lying between the casing and the end of the coil oflaminations, all of which continue into the center of the coil. In orderto at the same time obtain the desired narrowness and thickness of thisportion of the core, I bend the laminations in the portion of the coreextending transversely of the coil at an angle, preferably a rightangle, to the portions thereof extending through the center of the coilin the form shown herein to obtain the desired amount of iron in thecore at this point.

Other objects and advantages of the invention will appear as thedescription of the accompanying drawings proceeds. However, I desire tohave it distinctly understood that I do not intend to limit myself tothe exact details shown or described, but that I intend to include aspart of my invention all such obvious changes and modifica tions ofparts as would occur to a person skilled in this art and as would fallwithin the scope of the claims.

In the drawings:

Fig. 1 is a view partly in vertical section and partly in elevation ofan electro-magnetic clipper embodying my invention;

Fig. 2 is a plan view thereof showing the major portion of the coverbroken away and taken substantially on the line 22 of Fig. 1;

Fig. 3 is a section taken on the line 33 of Fig. 1; and

Fig. 4 is a perspective view of one of the laminations.

Referring in detail to the drawings, my invention is shown as beingapplied to a clipper having a casing comprising the main body portion 10and the cover 11, the cover being held in place on the main body portionby any suitable fastening means such as those indicated by the numeral12 in Fig. 2. The main body portion 10 of the casing is provided with apair of upwardly extending lugs or bossesvl3 for supporting theelectromagnet comprising the coil 14: on said casing.

The coil 14 is wound on a core comprising a central main core portion 15lying within and extending through the coil 14, a portion 16 extendingtransversely of the coil and portions 17 that. lie on opposite sides ofthe coil 14 and extend substantially parallel to the central coreportion 15. The transverse 1y extending portion 16, it will be noted, isquite narrow as compared to the ends 17 and hes between the side wall 18of the casing and the end of the coil 15 adjacent thereto, the otherside wall being indicated by the numeral 19 in Fig. 2. The end portions17 are made wider in order to provide suflicient material for extendingthe fastening means 20 through the same. While the portions 16 are madenarrow in order to reduce the width of the casing between the walls 18and 19 as much as possible and yet get as long a coil between said wallsas is possible without increasing the distance between said walls, theportion 16 is furthermore thickened in order to provide a greater amountof material in the portions of the core extending transversely of thecoil than would be possible, if the same were made an thicker-than thecentral portion 15 thereo In order to obtain the desired shape to thecore with the thickened transversely extending portion and yet have themagnetic flux travel through the iron throughout the length of the corewithout passlng acrossany air gaps, the laminations are made as shownmore clearly in Figs. 3 and 4.

Referring to Fig. 4, it will be seen that each lamination comprises acentral core formin portion 21 and cars 22 lying in substantia y thesame plane as the central core forming portion 21 to provide the ends 17for the core. A transversely extending portion 23 connects the ends orears 22 0 each lamination with the central portion 21. Said transverselyextending portion is bent or flanged as indicated at 24 to provide aportion extendingat an angle to the ends 22 and the central portion 21lying preferably. in a plane substantially at right angles to the planeof the portions 21 and 22. Preferably, the blanks are made substantiallyalike and are bent over or flanged after being assembled, the blanksbeing-held in proper relation by any suitable means so as not to shiftrelative to each other. This causes the flanges 23 to have a steppedformation, such Cooperating with the electro-magnet 1s a vibratoryarmature 26 carrying a movable clipper blade 27 which cooperates with astationary blade 28 in a well known manner. The armature 26 is offsetinwardly at 29 and 30 so as to have the said portions 29 and 30 thereoflie near the ends 17 of the core, thus having an ofiset to accommodatethe coil and core of the electro-magnet. Said vibratory member ispreferably clamped in position by suitable clamping means 31 and isvibrated by alternating current passing through the electro-magnet in awell known manner.

Having thus described my invention, what I desire to claim and secure byUnited States Letters Patent is:

1. In a device of the character described, a casing, an}'ele'ctrormagnet having a coil lying transversely of said casing and acore in said coil having a portion lying between the endyof said coiland said casing, said core comprising laminations having portionsextending at an angle to the axis of said coil lying between said casingand said coil.

2. In a device of the character described, a casing, an electro-magnethaving a coil lying transversely of said casing and a core in said coilhaving a portion lying between the end of said coil and said casing,said core being laminated, and the ortion thereof lying between the endof sai coil and said casing projecting transversely of said coil beyondthe portion thereof in said coil, all the laminations of said coreexternally of said coil extending into said coil.

a casing, an electro-magnet having a coil lying transversely of saidcasing and a core in said coil having a portion lying between the end ofsaid coil and said casing, said core comprising laminations havingportions extending substantially parallel to the axis of said coil andportions extending substantially perpendicularly to'said axis lyingbetween said casing and said coil.

4. In an electro-magnet, a core comprising laminations having flangesthereon extending. transversely of said core, said flanges havingprojections at the ends thereof extending parallel to and in the planesof said laminatio'ns;

5. In a device of the character described, a casing, an electro-magnethaving a coil lying transversely of said casing and a core in said coil,said core comprising laminations' having flat portions within said coilextending substantially parallel to the axis thereof and portions lyingbetween said casing and said coil extending tothe periphery of saidcoil, said casing and core having cooperating means thereon holding saidcoil in position transversely of and in spaced relation to said casing.

6. In a device of the character-described,

a casing, a pair of spaced supportstherein, an electro-magnet having acoil between said mamas 3 supports and a core in said coil, said corehaving oppositely directed portions extending outwardly be 0nd theCperipher of said c011 at one end t ereof an secure to said supports.

7 In a device of the character described, a casing, a pair of spacedsupports therein, an electro-magnet having a coil between said supportsand a core in said coil, said core comprising laminations havingportions inside said coil extending substantlally parallel to the axisthereof, portions outside said coil secured to said supports andintermediate portions extending transversely of said coil at one endthereof connecting said inside and outside portions.

8. In a device of the character described,

a casing, a pair of spaced supports therein, an electro-magnet having aC011 between said supports and a core in said coil, said core comprisinglaminations having portions inside said coil extending substantiallyparallel to the axis thereof, portions outside said coil secured to saidsupports and intermediate portions extending transversely of said coilat one end thereof connecting said inside and outside portions, saidintermediate portions being bent substantially right angles to the laneof said inside portions.

In witness whereof, I hereunto subscribe my name this th day ofSeptember, A. D. 1925.

\ LEO J. WAHL.

